Borrelia miyamotoi BipA-like protein, BipM, is a candidate serodiagnostic antigen distinguishing between Lyme disease and relapsing fever Borrelia infections.

A Borrelia miyamotoi gene with partial homology to bipA of relapsing fever spirochetes Borrelia hermsii and Borrelia turicatae was identified by a GenBank basic alignment search analysis. We hypothesized that this gene product may be an immunogenic antigen as described for other relapsing fever Borrelia (RFB) and could serve as a serological marker for B. miyamotoi infections. The B. miyamotoi gene was a truncated version about half the size of the B. hermsii and B. turicatae bipA with a coding sequence of 894 base pairs. The gene product had a calculated molecular size of 32.7 kDa (including the signal peptide). Amino acid alignments with B. hermsii and B. turicatae BipA proteins and with other B. miyamotoi isolates showed conservation at the carboxyl end. We cloned the B. miyamotoi bipA-like gene (herein named bipM) and generated recombinant protein for serological characterization and for antiserum production. Protease protection analysis demonstrated that BipM was surface exposed. Serologic analyses using anti-B. miyamotoi serum samples from tick bite-infected and needle inoculated mice showed 94 % positivity against BipM. The 4 BipM negative serum samples were blotted against another B. miyamotoi antigen, BmaA, and two of them were seropositive resulting in 97 % positivity with both antigens. Serum samples from B. burgdorferi sensu stricto (s.s.)-infected mice were non-reactive against rBipM by immunoblot. Serum samples from Lyme disease patients were also serologically negative against BipM except for 1 sample which may have indicated a possible co-infection. A recently published study demonstrated that B. miyamotoi BipM was non-reactive against serum samples from B. hermsii, Borrelia parkeri, and B. turicatae infected animals. These results show that BipM has potential for a B. miyamotoi-infection specific and sensitive serodiagnostic to differentiate between Lyme disease and various RFB infections.

Management of foreign body ingestion in adults: Time to STOP and rethink endoscopy.

Background and study aims Foreign body ingestion is a common cause for Emergency Department presentation. In adults, foreign body ingestion is more common in patients with underlying psychiatric comorbidity, the elderly, alcohol intoxication, and in prisoners. This study reviewed the management of patients presenting to a tertiary hospital with foreign body ingestion. Patients and methods A retrospective review of patients presenting with foreign body ingestion to a tertiary hospital in Melbourne, Victoria, was undertaken from January 2017 to December 2021. Data collected included patient demographics, type of foreign body, length of stay, imaging modalities, management strategies, and complications. High-risk ingestion was defined as sharp objects, length >5 cm, diameter >2.5 cm, button battery and/or magnet ingestion or esophageal as per international guidelines. Results A total of 157 presentations by 63 patients with foreign body ingestion occurred between 2017 and 2021 (50% male; median age 30 years). Of the patients, 56% had underlying psychiatric comorbidities. The majority of presentations occurred in prisoners (65%). The most commonly ingested objects were batteries (23%), alleged drug-containing balloons (17%), razor blades (16%), and miscellaneous (40%). High-risk ingestion occurred in approximately two-thirds of presentations. Conservative management was the most common approach in 55% of patients. Complications, defined as perforation, bowel obstruction or fistula formation, did not occur in this cohort despite more than half presenting with high-risk ingestions. Thirty-day re-presentation rates were high (31%) and that was most common in patients with intentional ingestion, underlying mental health disorders, and a documented history of self-harm. Conclusions Conservative management for patients presenting with recurrent high-risk foreign body ingestion was safe in appropriately selected cases. Re-presentation is common and poses significant challenges for health care providers.

Factors associated with long-term healthcare expense and steroid exposure in patients admitted with acute severe ulcerative colitis.

Background and Aim: Acute severe ulcerative colitis (ASUC) remains a significant cause of morbidity and healthcare utilization. This study aimed to characterize the total healthcare costs of ASUC, explore factors associated with significant cost over the 12 months following an index admission, and document outcomes including corticosteroid exposure. Methods: Patients admitted from January 2016 until January 2021 for ASUC to a tertiary inflammatory bowel disease (IBD) center in Australia were identified via retrospective chart review. Costs were calculated over a 12-month period following index admission. Results: Seventy-two patients (30 [42%] female, median age 39 [IQR 27-54] years) were included. The median length of stay of index admission was 6 days (IQR 5-10 days). The median cost of index admission was 7829 AUD, which was driven by the initial length of stay (P < 0.01) and requirement for colectomy (P < 0.01). Median total healthcare cost over the first 12 months was 13 873 AUD (IQR 9684-19 936 AUD), again predominately driven by the length of stay (P < 0.01) and requirement for colectomy (P < 0.01). Median cumulative corticosteroid use over 12 months inclusive of index hospitalization was 1760 mg (IQR 1560-2350 mg). Requirement for inpatient medical salvage therapy with infliximab was associated with increased corticosteroid requirement (P = 0.01). Conclusion: Healthcare expense related to ASUC remains high, driven predominantly by the length of stay during initial hospitalization and need for colectomy. From a healthcare cost perspective, novel methods to reduce inpatient hospital stay as well as need for colectomy may help reduce the economic and steroid burden of ASUC.

Upadacitinib Salvage Therapy for Infliximab-Experienced Patients with Acute Severe Ulcerative Colitis.

BACKGROUND AND AIMS: Acute severe ulcerative colitis [ASUC] is a medical emergency treated with intravenous steroids followed by infliximab or cyclosporin in the case of steroid failure with emergent colectomy required in refractory or severe cases. Case series have reported on the effectiveness of tofacitinib for refractory disease, but data regarding the effectiveness of upadacitinib in this setting have not been previously reported. We describe the use of upadacitinib therapy for steroid-refractory ASUC in patients with prior loss of response to infliximab. METHODS: Six patients who received upadacitinib for steroid-refractory ASUC were identified at two Australian tertiary inflammatory bowel disease centres. Patients were followed for up to 16 weeks after discharge with clinical, biochemical and intestinal ultrasound [IUS] outcomes. RESULTS: All six patients demonstrated clinical response to upadacitinib induction during their inpatient admission. Four patients achieved corticosteroid-free clinical remission by week 8, including complete resolution of rectal bleeding and transmural healing assessed by IUS, and sustained clinical remission at week 16. One patient proceeded to colectomy at week 15 due to refractory disease. No adverse events directly attributable to upadacitinib were identified. CONCLUSIONS: Upadacitinib may have a role as a safe and effective salvage therapy for steroid-refractory ASUC in patients who have previously failed to respond to infliximab therapy. Prospective studies are required to determine the safety and efficacy of upadacitinib use in this setting before routine use can be recommended.

Structural Elucidation of a Protective B Cell Epitope on Outer Surface Protein C (OspC) of the Lyme Disease Spirochete, Borreliella burgdorferi.

Outer surface protein C (OspC) plays a pivotal role in mediating tick-to-host transmission and infectivity of the Lyme disease spirochete, Borreliella burgdorferi. OspC is a helical-rich homodimer that interacts with tick salivary proteins, as well as components of the mammalian immune system. Several decades ago, it was shown that the OspC-specific monoclonal antibody, B5, was able to passively protect mice from experimental tick-transmitted infection by B. burgdorferi strain B31. However, B5's epitope has never been elucidated, despite widespread interest in OspC as a possible Lyme disease vaccine antigen. Here, we report the crystal structure of B5 antigen-binding fragments (Fabs) in complex with recombinant OspC type A (OspCA). Each OspC monomer within the homodimer was bound by a single B5 Fab in a side-on orientation, with contact points along OspC's α-helix 1 and α-helix 6, as well as interactions with the loop between α-helices 5 and 6. In addition, B5's complementarity-determining region (CDR) H3 bridged the OspC-OspC' homodimer interface, revealing the quaternary nature of the protective epitope. To provide insight into the molecular basis of B5 serotype specificity, we solved the crystal structures of recombinant OspC types B and K and compared them to OspCA. This study represents the first structure of a protective B cell epitope on OspC and will aid in the rational design of OspC-based vaccines and therapeutics for Lyme disease. IMPORTANCE The spirochete Borreliella burgdorferi is a causative agent of Lyme disease, the most common tickborne disease in the United States. The spirochete is transmitted to humans during the course of a tick taking a bloodmeal. After B. burgdorferi is deposited into the skin of a human host, it replicates locally and spreads systemically, often resulting in clinical manifestations involving the central nervous system, joints, and/or heart. Antibodies directed against B. burgdorferi's outer surface protein C (OspC) are known to block tick-to-host transmission, as well as dissemination of the spirochete within a mammalian host. In this report, we reveal the first atomic structure of one such antibody in complex with OspC. Our results have implications for the design of a Lyme disease vaccine capable of interfering with multiple stages in B. burgdorferi infection.

Analysis of variable major protein antigenic variation in the relapsing fever spirochete, Borrelia miyamotoi, in response to polyclonal antibody selection pressure.

Borrelia miyamotoi is a tick-transmitted spirochete that is genetically grouped with relapsing fever Borrelia and possesses multiple archived pseudogenes that encode variable major proteins (Vmps). Vmps are divided into two groups based on molecular size; variable large proteins (Vlps) and variable small proteins (Vsps). Relapsing fever Borrelia undergo Vmp gene conversion at a single expression locus to generate new serotypes by antigenic switching which is the basis for immune evasion that causes relapsing fever in patients. This study focused on B. miyamotoi vmp expression when spirochetes were subjected to antibody killing selection pressure. We incubated a low passage parent strain with mouse anti-B. miyamotoi polyclonal antiserum which killed the majority population, however, antibody-resistant reisolates were recovered. PCR analysis of the gene expression locus in the reisolates showed vsp1 was replaced by Vlp-encoded genes. Gel electrophoresis protein profiles and immunoblots of the reisolates revealed additional Vlps indicating that new serotype populations were selected by antibody pressure. Sequencing of amplicons from the expression locus of the reisolates confirmed the presence of a predominant majority serotype population with minority variants. These findings confirm previous work demonstrating gene conversion in B. miyamotoi and that multiple serotype populations expressing different vmps arise when subjected to antibody selection. The findings also provide evidence for spontaneous serotype variation emerging from culture growth in the absence of antibody pressure. Validation and determination of the type, number, and frequency of serotype variants that arise during animal infections await further investigations.

Evaluation of Immunocompetent Mouse Models for Borrelia miyamotoi Infection.

Borrelia miyamotoi is a relapsing fever spirochete that is harbored by Ixodes spp. ticks and is virtually uncharacterized, compared to other relapsing fever Borrelia vectored by Ornithodoros spp. ticks. There is not an immunocompetent mouse model for studying B. miyamotoi infection in vivo or for transmission in the vector-host cycle. Our goal was to evaluate B. miyamotoi infections in multiple mouse breeds/strains as a prelude to the ascertainment of the best experimental infection model. Two B. miyamotoi strains, namely, LB-2001 and CT13-2396, as well as three mouse models, namely, CD-1, C3H/HeJ, and BALB/c, were evaluated. We were unable to observe B. miyamotoi LB-2001 spirochetes in the blood via darkfield microscopy or to detect DNA via real-time PCR post needle inoculation in the CD-1 and C3H/HeJ mice. However, LB-2001 DNA was detected via real-time PCR in the blood of the BALB/c mice after needle inoculation, although spirochetes were not observed via microscopy. CD-1, C3H/HeJ, and BALB/c mice generated an antibody response to B. miyamotoi LB-2001 following needle inoculation, but established infections were not detected, and the I. scapularis larvae failed to acquire spirochetes from the exposed CD-1 mice. In contrast, B. miyamotoi CT13-2396 was visualized in the blood of the CD-1 and C3H/HeJ mice via darkfield microscopy and detected by real-time PCR post needle inoculation. Both mouse strains seroconverted. However, no established infection was detected in the mouse organs, and the I. scapularis larvae failed to acquire Borrelia after feeding on CT13-2396 exposed CD-1 or C3H/HeJ mice. These findings underscore the challenges in establishing an experimental B. miyamotoi infection model in immunocompetent laboratory mice. IMPORTANCE Borrelia miyamotoi is a causative agent of hard tick relapsing fever, was first identified in the early 1990s, and was characterized as a human pathogen in 2011. Unlike other relapsing fever Borrelia species, B. miyamotoi spread by means of Ixodes ticks. The relatively recent recognition of this human pathogen means that B. miyamotoi is virtually uncharacterized, compared to other Borrelia species. Currently there is no standard mouse-tick model with which to study the interactions of the pathogen within its vector and hosts. We evaluated two B. miyamotoi isolates and three immunocompetent mouse models to identify an appropriate model with which to study tick-host-pathogen interactions. With the increased prevalence of human exposure to Ixodes ticks, having an appropriate model with which to study B. miyamotoi will be critical for the future development of diagnostics and intervention strategies.

Clinical exome sequencing of 1000 families with complex immune phenotypes: Toward comprehensive genomic evaluations.

BACKGROUND: Prospective genetic evaluation of patients at this referral research hospital presents clinical research challenges. OBJECTIVES: This study sought not only a single-gene explanation for participants' immune-related presentations, but viewed each participant holistically, with the potential to have multiple genetic contributions to their immune phenotype and other heritable comorbidities relevant to their presentation and health. METHODS: This study developed a program integrating exome sequencing, chromosomal microarray, phenotyping, results return with genetic counseling, and reanalysis in 1505 individuals from 1000 families with suspected or known inborn errors of immunity. RESULTS: Probands were 50.8% female, 71.5% were ≥18 years, and had diverse immune presentations. Overall, 327 of 1000 probands (32.7%) received 361 molecular diagnoses. These included 17 probands with diagnostic copy number variants, 32 probands with secondary findings, and 31 probands with multiple molecular diagnoses. Reanalysis added 22 molecular diagnoses, predominantly due to new disease-gene associations (9 of 22, 40.9%). One-quarter of the molecular diagnoses (92 of 361) did not involve immune-associated genes. Molecular diagnosis was correlated with younger age, male sex, and a higher number of organ systems involved. This program also facilitated the discovery of new gene-disease associations such as SASH3-related immunodeficiency. A review of treatment options and ClinGen actionability curations suggest that at least 251 of 361 of these molecular diagnoses (69.5%) could translate into ≥1 management option. CONCLUSIONS: This program contributes to our understanding of the diagnostic and clinical utility whole exome analysis on a large scale.

Systematic review and meta-analysis: evaluating response to empiric anti-TNF dose intensification for secondary loss of response in Crohn's disease.

INTRODUCTION: Anti-tumor necrosis factor (TNF) dose intensification represents an effective method of overcoming secondary loss of response (LOR); however, a subset of patients may not respond (tertiary non-response), or fail to demonstrate durable response (tertiary LOR) to intensified dosing. This systematic review and meta-analysis aimed to evaluate these outcomes to determine the clinical effectiveness of empiric dose intensification in Crohn's disease. METHODS: Multiple databases including MEDLINE and EMBASE were interrogated to identify studies that reported outcomes following anti-TNF dose intensification to address secondary LOR in Crohn's disease. Studies that used anti-TNF levels as the primary basis for dose intensification were excluded. Studies that reported (1) tertiary response and tertiary non-response within 6 months or (2) tertiary response and tertiary LOR beyond 6 months, were pooled using a random effects model with risk ratio (RR) derived, quantifying the effect of each comparison. RESULTS: Twenty-six studies reported outcomes following anti-TNF dose intensification to address secondary LOR. Short-term response within 12 weeks of any dose-intensification strategy was 33-90%, while sustained response (⩾48 weeks) was achieved in 25-85%. Tertiary non-response occurred in up to 45% of intensified patients within 6 months of anti-TNF dose intensification, while tertiary LOR beyond 6 months occurred in up to 64% of patients. Tertiary response was more likely than tertiary non-response within 6 months (RR 2.58, 95% CI (1.76, 3.79), I 2 = 82%, 12 studies), while sustained response beyond 6 months compared to tertiary LOR (RR 1.10 (0.75, 1.61) I 2 = 85%, 7 studies) was less convincing. CONCLUSION: Although anti-TNF dose intensification is clinically effective in patients with Crohn's disease, particularly within the first 6 months, a proportion of patients will fail to demonstrate short-term and/or sustained clinical response. Hence, clinical reassessment following anti-TNF dose intensification, particularly beyond 6 months, remains important to differentiate between effective and ineffective dose-intensification strategies.

Cytomegalovirus in inflammatory bowel disease: a clinical approach.

Cytomegalovirus (CMV) infection can be a challenging clinical problem in patients with inflammatory bowel disease (IBD), particularly ulcerative colitis. Clinical presentation is difficult to distinguish from an underlying disease flare. Several diagnostic modalities are now available and when combined can aid clinicians in the identification of patients who are most likely to benefit from antiviral therapy. The aim of this article is to review the available literature and outline a practical approach to the diagnosis and management of CMV in patients with IBD.

Modification of the multiplex plasmid PCR assay for Borrelia miyamotoi strain LB-2001 based on the complete genome sequence reflecting genomic rearrangements differing from strain CT13-2396.

The genome of Borrelia spp. consists of an approximate 1 megabase chromosome and multiple linear and circular plasmids. We previously described a multiplex PCR assay to detect plasmids in the North American Borrelia miyamotoi strains LB-2001 and CT13-2396. The primer pair sets specific for each plasmid were derived from the genome sequence for B. miyamotoi strain CT13-2396, because the LB-2001 complete sequence had not been generated. The recent completion of the LB-2001 genome sequence revealed a distinct number of plasmids (n = 12) that differed from CT13-2396 (n = 14). Notable was a 97-kilobase plasmid in LB-2001, not present in CT13-2396, that appeared to be a rearrangement of the circular plasmids of strain CT13-2396. Strain LB-2001 contained two plasmids, cp30-2 and cp24, that were not annotated for strain CT13-2396. Therefore, we re-evaluated the original CT13-2396-derived multiplex PCR primer pairs and determined their location in the LB-2001 plasmids. We modified the original multiplex plasmid PCR assay for strain LB-2001 to include cp30-2 and cp24. We also determined which LB-2001 plasmids corresponded to the amplicons generated from the original CT13-2396 primer sets. These observations provide a more precise plasmid profile based on the multiplex PCR assay and reflect the complexity of gene rearrangements that occur in B. miyamotoi strains isolated from the same geographic region.

Higher Anti-tumor Necrosis Factor-α Levels Correlate With Improved Radiologic Outcomes in Crohn's Perianal Fistulas.

BACKGROUND & AIMS: Higher anti-tumor necrosis factor-α (TNF) drug levels are associated with improved clinical healing of Crohn's perianal fistulas. It is unclear whether this leads to improved healing on radiologic assessment. We aimed to evaluate the association between anti-TNF drug levels and radiologic outcomes in perianal fistulising Crohn's disease. METHODS: A cross-sectional retrospective multicenter study was undertaken. Patients with perianal fistulising Crohn's disease on maintenance infliximab or adalimumab, with drug levels within 6 months of perianal magnetic resonance imaging were included. Patients receiving dose changes or fistula surgery between drug level and imaging were excluded. Radiologic disease activity was scored using the Van Assche Index, with an inflammatory subscore calculated using indices: T2-weighted imaging hyperintensity, collections >3 mm diameter, rectal wall involvement. Primary endpoint was radiologic healing (inflammatory subscore ≤6). Secondary endpoint was radiologic remission (inflammatory subscore = 0). RESULTS: Of 193 patients (infliximab, n = 117; adalimumab, n = 76), patients with radiologic healing had higher median drug levels compared with those with active disease (infliximab 6.0 vs 3.9 µg/mL; adalimumab 9.1 vs 6.2 µg/mL; both P < .05). Patients with radiologic remission also had higher median drug levels compared with those with active disease (infliximab 7.4 vs 3.9 µg/mL; P < .05; adalimumab 9.8 vs 6.2 µg/mL; P = .07). There was a significant incremental reduction in median inflammatory subscores with higher anti-TNF drug level tertiles. CONCLUSIONS: Higher anti-TNF drug levels were associated with improved radiologic outcomes on magnetic resonance imaging in perianal fistulising Crohn's disease, with an incremental improvement at higher drug level tertiles for both infliximab and adalimumab.

Sequential Use of High-Dose Tofacitinib After Infliximab Salvage Therapy in Acute Severe Ulcerative Colitis.

BACKGROUND AND AIMS: Preliminary data regarding the effectiveness of tofacitinib in acute severe ulcerative colitis [ASUC] have been presented in two previous case series. We aimed to describe the novel use of high-dose tofacitinib immediately following non-response to infliximab in the setting of steroid-refractory ASUC. METHODS: Five patients who received high-dose tofacitinib 10 mg three times a day immediately following non-response to infliximab for steroid-refractory ASUC were identified at an Australian tertiary inflammatory bowel disease centre. RESULTS: Four of the five patients demonstrated clinical response to high-dose tofacitinib induction during their inpatient admission, with one patient requiring colectomy owing to a lack of clinical response. At 90 days, all four initial responders remained colectomy-free, with two patients achieving combined clinical and endoscopic remission. No adverse events directly attributable to high-dose tofacitinib were identified. CONCLUSIONS: High-dose tofacitinib may have a role as salvage therapy in the setting of steroid-refractory ASUC. Prospective studies are required to determine the safety and efficacy of high-dose tofacitinib to determine whether it can be routinely recommended as primary or sequential salvage therapy in the setting of steroid-refractory ASUC.

Some elements for a history of the dynamical systems theory.

Writing a history of a scientific theory is always difficult because it requires to focus on some key contributors and to "reconstruct" some supposed influences. In the 1970s, a new way of performing science under the name "chaos" emerged, combining the mathematics from the nonlinear dynamical systems theory and numerical simulations. To provide a direct testimony of how contributors can be influenced by other scientists or works, we here collected some writings about the early times of a few contributors to chaos theory. The purpose is to exhibit the diversity in the paths and to bring some elements-which were never published-illustrating the atmosphere of this period. Some peculiarities of chaos theory are also discussed.

A transwell assay method to evaluate Borrelia burgdorferi sensu stricto migratory chemoattraction toward tick saliva proteins.

We developed a transwell assay to quantify migration of the Lyme disease agent, Borrelia burgdorferi sensu stricto (s.s.), toward Ixodes scapularis salivary gland proteins. The assay was designed to assess B. burgdorferi s.s. migration upward against gravity through a transwell polycarbonate membrane overlaid with 6% gelatin. Borreliae that channeled into the upper transwell chamber in response to test proteins were enumerated by flow cytometry. The transwell assay measured chemoattractant activity for B. burgdorferi s.s. from salivary gland extract (SGE) harvested from nymphal ticks during bloodmeal engorgement on mice 42 h post-attachment and saliva collected from adult ticks. Additionally, SGE protein fractions separated by size exclusion chromatography demonstrated various levels of chemoattractant activity in the transwell assay. Sialostatin L, and Salp-like proteins 9 and 11 were identified by mass spectrometry in SGE fractions that exhibited elevated activity. Recombinant forms of these proteins were tested in the transwell assay and showed positive chemoattractant properties compared to controls and another tick protein, S15A. These results were reproducible providing evidence that the transwell assay is a useful method for continuing investigations to find tick saliva components instrumental in driving B. burgdorferi s.s. chemotaxis.